A fire alarm system can be installed such that it has multiple circuits that are terminated adjacent to each other. Of interest is the case where these circuits are addressable loops that are used to communicate to multiple circuits of addressable fire alarm devices. In some cases, these wires are part of a cable in which the conductors are bundled together and which aids in properly identifying the pairs of wires.
In other cases, for example using THHN wire, the wires are discrete conductors. In these situations, the wires are commonly colored to identify polarity. It is possible to mix up the wires such that a black and white wire pair will terminate as a circuit when in fact they are wired to different loops of devices. This mis-wire may not be detected, since each circuit is complete across multiple loops. However, if a wiring fault, such as a short circuit, should develop on one loop, two loops will be affected.